Lawn-Boy
Gas Walk-Behind Mower

Model #S21ZPR Official Lawn-Boy lawn mower

Here are the diagrams and repair parts for Lawn-Boy S21ZPR lawn mower, as well as links to manuals and error code tables, if available.

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  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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For DIY troubleshooting advice and repair guides, visit our repair help section.

    Showing 10 of 185 parts

    Lawn & Garden Equipment 2-Cycle Engine Oil, 6-pack

    #NI

    All parts Diagram

    2 cycle oil

    Part #33600
    Replaced by #21603
    ?
    Manufacturer substitution
    This part replaces 33600. Substitute parts can look different from the original.

    Get free shipping with Automatic Reorder

    In Stock
    $9.99 | 
    9% OFF 
    Phone Price: $10.99
    Case Assembly#52

    Engine group Diagram

    Case assembly

    Part #683819
    Replaced by #93-4301
    ?
    Manufacturer substitution
    This part replaces 683819. Substitute parts can look different from the original.
    In Stock
    $16.44
    Screw

    See All Related Diagrams

    Hex screw

    Part #609891
    Replaced by #700138
    ?
    Manufacturer substitution
    This part replaces 609891. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $4.65
    Washer#18

    Housing and shroud group Diagram

    Washer

    Part #608834
    Replaced by #608834
    ?
    Manufacturer substitution
    This part replaces 608834. Substitute parts can look different from the original.
    In Stock
    $16.45
    Plate#28

    Engine group Diagram

    Plate

    Part #602587
    Replaced by #602587
    ?
    Manufacturer substitution
    This part replaces 602587. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $3.13
    Screw#27

    Engine group Diagram

    Screw

    Part #612872

    The manufacturer no longer makes this part, and there's no substitute part

    Tie Strap

    See All Related Diagrams

    Tie strap

    Part #614249
    Replaced by #614249
    ?
    Manufacturer substitution
    This part replaces 614249. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $2.16
    Snowblower Screw#1

    Handle group Diagram

    Carriage bolt

    Part #800358
    Replaced by #3230-22
    ?
    Manufacturer substitution
    This part replaces 800358. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $2.82
    Lawn Mower Screw#20

    Handle group Diagram

    Screw

    Part #145498
    Replaced by #614697
    ?
    Manufacturer substitution
    This part replaces 145498. Substitute parts can look different from the original.
    This item is not returnable
    In Stock
    $2.16
    Bearing#18

    Engine group Diagram

    Bearing

    Part #679144

    The manufacturer no longer makes this part, and there's no substitute part

    Symptoms for gas walk-behind mowers

    Choose a symptom to see related walk-behind mower repairs.

    Main causes: uneven wheel height settings, damaged wheel, dull or damaged cutting blade
    Main causes: damaged cutting blade, loose cutting blade, damaged flywheel key, engine needs tune up
    Main causes: dirty carburetor, bad spark plug, clogged air filter, engine choke problems, clogged gas cap vent
    Main causes: engine needs tune up, dirty or clogged carburetor, damaged flywheel key
    Main causes: drive control cable failure, worn or broken drive belt, bad transmission, broken drive wheel
    Main causes: stale gas, engine needs tune up, bad spark plug, dead battery, bad recoil starter, faulty safety switch, bad ignition coil

    Repair guides for gas walk-behind mowers

    These step-by-step repair guides will help you safely fix what’s broken on your walk-behind lawn mower.

    March 1, 2016
    By Lyle Weischwill
    How to replace a lawn mower blade

    Check your lawn mower blade regularly and replaced it if it's bent or damaged.

    Repair difficulty
    Time required
     15 minutes or less
    How to replace a lawn mower ignition coil on an OHV engine

    Replace the ignition coil if it isn't sending electric current to the spark plug when you pull the recoil starter rope.

    Repair difficulty
    Time required
     30 minutes or less
    How to replace a lawn mower flywheel key on a flathead engine

    When you hit a hard object with your mower, the flywheel can shear to protect more expensive components. Learn how to replace this tiny but essential part.

    Repair difficulty
    Time required
     45 minutes or less

    Articles and videos common to all walk-behind mowers

    Use the advice and tips in these articles and videos to get the most out of your walk-behind lawn mower.

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    Introducing new technical repair content that we’re developing for the Sears Technical Institute

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    Learn about Sears Technical Institute and the advanced technical content being developed for aspiring appliance techs.

    June 29, 2022

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